Internal steam engine

ABSTRACT

An internal steam engine comprising one or more cylinders containing pistons, injectors and heating means. Air is drawn into said cavities and compressed as the piston reaches top dead center. The injector means spray the charge of heated compressed air with a non-combustible liquid which is vaporized under constant pressure followed by expansion and power stroke by the piston. The exhaust of the air mixture from the piston cavity is released through the liquid supply tank where the vapor is condensed and recycled to complete a closed operating cycle. A new charge is taken in at the end of the exhaust following either a four- or two-stroke engine process. The heating means are controlled by the cylinder temperature and activated to provide heat to the compression as required. In difference to a conventional steam engine, which generates steam from water in a boiler outside the working cylinder, the internal steam engine vaporizes water intermittently inside the working cylinder and exclusively in each compressed air charge to initiate a power stroke by the piston.

BACKGROUND OF THE INVENTION

The present invention relates to two- and four-stroke internal combustion engines in which useful work is generated from combustion of oxidizer and fuel which expansion acts upon the top of an reciprocating piston. Such engines use either spark ignition or compression ignition for the combustion of the air-fuel mixture. The basic components of the engines include the engine block, cylinder head, cylinders, pistons, valves, crankshaft and flywheel. Such combustion engines are fueled by refined petroleum products and constitute the main power source for vehicle locomotion in the world today. The sheer quantity of oil being burnt for this purpose represent a growing threat to our environment by emission of carbon dioxide which, greenhouse gas, allegedly is the main contributor to the present trend of global warming. The world demand for oil also gives rise to geopolitical supply problems involving national security and economic instability.

In view of the above, it would be desirable to operate the time tested mechanical design of the two- and four-stroke compression engines in another mode so as to eliminate the need for petrol fuel and its poisonous emissions. This could be accomplished by an internal steam engine where, analogous to the compression-ignition cycle of a diesel engine, a non-combustible liquid is injected into the high temperature compressed air at the top of the cylinder cavity to generate steam which expansion forces the piston into a power stroke.

SUMMARY OF THE INVENTION

In summary, the internal steam engine injects a non-combustible liquid inside the mechanical structure and operational characteristics of the common diesel engine. In contrast to the diesel process, the steam power stroke is accomplished at lower operational temperature and without emission of noxious gases. In comparison with conventional steam engines, which generates steam uninterruptedly in a boiler outside the piston cylinder, the internal steam engine generates steam intermittently to coincide with the compressed air charge inside the cylinder and in the appropriate volume desired for each power stroke of the piston. These and other advantages of the internal steam engine will become apparent in the remainder of this disclosure.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a four-stroke engine cylinder.

FIG. 2 is a cross-sectional view of a two-stroke engine cylinder.

FIG. 3 is a schematic view of a piston in the air intake stroke.

FIG. 4 is a schematic view of a piston in the compression stroke.

FIG. 5 is a schematic view of a piston in the injection process.

FIG. 6 is a schematic view of a piston in the power stroke.

FIG. 7 is a schematic view of a piston in the air exhaust stroke depicting the condensation recycling process.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIG. 1, a four-stroke version of an internal steam engine includes a crankcase 1, a rotary crankshaft 2, connected to rod 3, affixed to piston 4, cylinder 5, cylinder head 6, pre-chamber 7, exhaust valve 8, intake valve 9, injector 10 and heating element 11.

With reference to FIG. 2, a two-stroke version of an internal steam engine includes a crankcase 12, a rotary crankshaft 13, rod 14, piston 15, cylinder 17, cylinder head 18, pre-chamber 19, air intake ports 20, exhaust valve 21, injector 22, and heating element 23.

In a four-stroke embodiment of the invention, the cycle of the internal steam engine comprises six main stages which are air intake, compression, steam generation, expansion, exhaust and condensation as outlined schematically in the following figures.

FIG. 3—Air Intake: The piston is moving from top dead center to bottom dead center to draw in fresh air through the opening of the intake valve.

FIG. 4—Compression: While the intake valve is closing, the piston is compressing the air charge by moving from bottom dead center to the top dead center which process contributes work to the air. The compression is determined by the designed volumetric compression ratio, which is the ratio of the volume of working air before the compression to its volume after, and establishes the temperature substantially above the water to steam point.

FIG. 5—Steam Generation: Injector injects a spray of non-combustible liquid into the hot pressurized air which causes instant liquid to steam convergence within a constant pressure process.

FIG. 6—Expansion: The liquid to steam expansion contributes the useful work of the engine as it forces the piston down in the cylinder to rotate the crankshaft.

FIG. 7—Exhaust; By the upward return stroke of the piston, the expanded vapor air mixture is forced through the exhaust valve and cooled down to ambient conditions as it enters to the liquid storage tank to be condensed and recycled.

A two-stroke engine cycle is outlined below with reference to FIG. 2.

-   -   At its bottom position, piston 15 is uncovering ports 20 to         admit a fresh charge of air into cylinder 17.     -   As piston 15 is moving up, it compresses a charge of hot air at         the top of cylinder 17. Non-combustible liquid is sprayed into         said compressed hot air by injector 22 inside pre-chamber 19 in         cylinder head 18 where it converts to steam due to the heat and         pressure inside cylinder 17.     -   The pressure created by the liquid to steam expansion drives         piston 15 down in the power stroke.     -   As piston 15 nears the bottom of its stroke, the exhaust valves         21 open to allow the air mixture to escape and cool down to         ambient conditions as it is channeled to a liquid storage tank         to be condensed and recycled. Alternatively, the exhaust may be         accomplished through a ring of exhaust ports, mounted radially         around the center of the cylinder, when uncovered by piston 15         on its downward stroke. Here not illustrated.     -   As piston 15 bottoms, it uncovers the intake ports 20 to receive         a new air charge. Finally, although the internal steam engine as         shown discloses a certain heating element to facilitate the         starting of the engine, it should be understood that other types         of heating arrangements may be used to accomplish this purpose.         Method of Use

The internal steam engine is adaptable to replace the internal combustion engine in vehicles powered by such means. The size and mechanical features of the internal steam engine is similar to those of the combustion engine where the crankshaft provides the driving force of the vehicle.

The method of use of the internal steam engine of this invention includes a power source for a generator to supply current to a battery array and electric motor in electric and hybrid vehicles. Currently, the electricity to charge the battery array in such vehicles is produced by a generator which is powered by an internal combustion engine. This operation requires the burning of fuel with accompanying emission of noxious gases.

Hybrid electrical vehicles are driven by an electric motor powered by a battery array which is recharged by a generator. Application of an internal steam engine in such a vehicle is intended to supply power to the generator as well as mechanically drive the vehicle with or without input from the electric motor.

Another adaptation of the internal steam engine is the conversion of an existing internal combustion engine to operate on the internal steam principle. Basically, it involves replacing the cylinder head with one containing injector and heating means and configured to give the desired volumetric compression.

It is thought that the invention and its numerous attendant advantages will be fully understood from the foregoing description, and it is obvious that numerous changes may be made in the form, construction and arrangement of the several parts without departing from the spirit or scope of the invention, or sacrificing any of its attendant advantages, the form herein disclosed being preferred embodiments for the purpose of illustrating the invention. 

1. An internal steam engine comprising a two- or four-stroke cycle engine with one or more cylinders, a piston reciprocating in said cylinder and operatively connected to a crankshaft, exhaust and intake passage means, injector and heating means connected to the top portion of said cylinder, said piston compressing an air charge into said top portion of the cylinder, said injector means to inject a non-combustible liquid spray into said compressed air charge, said liquid spray being vaporized by heat generated by said compressed air charge, said vapor expanding to force said piston downward in said cylinder to drive said crankshaft, said vapor condensed and re-cycled in a closed operating cycle.
 2. An internal steam engine as claimed in claim 1, wherein said heat generated by the compressed air charge is supplemented by said heating means.
 3. An internal steam engine as claimed in claim 2, wherein said heating means are electrically operated.
 4. An internal steam engine as claimed in claim 1, wherein said injector and heating means are operational inside a pre-chamber recess in said top portion of said cylinder and controlled by the temperature therein.
 5. An internal steam engine as claimed in claim 1, wherein said injector means injects a spray of combustible liquid into said compressed air charge to supplement the heat generated by said compressed air charge.
 6. An internal steam engine as claimed in claim 1, wherein said injector means may inject any other liquid to obtain vapor from heat generated from said compressed air charge.
 7. An internal steam engine as claimed in claim 1, wherein said internal steam engine provides power to drive a vehicle through mechanical means.
 8. An internal steam engine as claimed in claim 1, wherein said internal steam engine power a generator to drive a vehicle by electrical means. 